Integrins are a superfamily of cell adhesion receptors, which are transmembrane glycoproteins expressed on a variety of cells. These cell surface adhesion receptors include gpIIb/IIIa (the fibrinogen receptor) and αvβ3 (the vitronectin receptor). The fibrinogen receptor gpIIb/IIIa is expressed on the platelet surface, and mediates. The vitronectin receptor is known to refer to three different integrins, designated αvβ1, αvβ3 and αvβ5 Compounds that inhibit the activity of these receptors and associated integrins may be useful for the treatment of inflammation, cancer and cardiovascular disorders, such as atherosclerosis and restenosis, and diseases wherein bone resorption is a factor, such as osteoporosis. Benzazepine compounds that are potent inhibitors of the αvβ3 and αvβ5 receptors are described in U.S. Pat. Nos. 5,939,412 and 6,127,359.
Each of the above publications describes a variety of procedures for constructing benzazepines, however these processes employ expensive reagents and generally require a large number of steps in the synthetic sequence. Accordingly, it would be useful to develop an efficient and cost-effective process for the preparation of benzazepine compounds.